Various techniques are known in the art for spatially mapping cardiac signals in a heart cavity. For example, U.S. Patent Application Publication 2011/0190625, whose disclosure is incorporated herein by reference, describes a non-contact cardiac mapping method that includes: (i) inserting a catheter into a heart cavity having an endocardium surface, the catheter including multiple, spatially distributed electrodes; (ii) measuring signals at the catheter electrodes in response to electrical activity in the heart cavity with the catheter spaced from the endocardium surface; and (iii) determining physiological information at multiple locations of the endocardium surface based on the measured signals and positions of the electrodes with respect to the endocardium surface. Related systems and computer programs are also disclosed.
U.S. patent application Publication 2009/0306641, whose disclosure is incorporated herein by reference, describes a method for providing an electro-anatomical representation of a patient's heart which includes measuring signals at one or more electrodes at multiple positions in the patient's heart cavity over a time period including multiple heart beat cycles, at least some of the signals being in response to electrical activity in the patient's heart cavity. An algorithm is applied to one or more specific signals of the measured signals to determine a triggering event in the specific signal. The signals measured at the one or more electrodes are synchronized by the computer with one another according to a heartbeat cycle based on the triggering event. The electro-anatomical representation of the patient's heart is generated by the computer based on the synchronized measured signals and positions of the catheter electrodes.